Part One: Interview with Mary E. Schiavoni, MS, CCC-SLP Speech-Language Pathologist, Feeding Consultant, Pediatric Neurodevelopmental Therapist

1. What is your background and what led to the design of the Chewy Tube?

From the earliest days of my professional career I have had an interest in specializing in the pediatric field, working with children having special needs. In addition to my educational preparation as a Speech and Language Pathologist, I also acquired certification as an Elementary Education Teacher, and in the area of Special Education, as a Teacher of the Mentally Impaired in the mild, moderate and severe ranges of impairment. Later in my work experience, I added Teacher of the Emotionally Impaired to my resume. In addition I have an extensive educational and experiential background in Applied Behavior Analysis.

I graduated with a Bachelor of Science in Speech and Audiology from Western Michigan University in Kalamazoo, MI. After working in the field for a number of years, I completed my Master’s at the University of South Florida in Tampa, FL, I continued my professional training with certification as a Pediatric Neurodevelopmental Therapist under the training of Dr. Christine Nelson in Cuernavaca, Mexico. This training, focusing on the central nervous system, opened up a deeper multidimensional perspective to my treatment as a SLP, on top of which I added training in craniosacral and myofascial treatment.

I also had an interest from the earliest days of my career to focus on the fundamental skills involved in speech production and oral motor function. I began to target function of the tongue and jaw in treatment with my patients and read every book and article I could get my hands on regarding pediatric feeding. At this time I also served a population of children with significant special needs at the Arizona Children’s Hospital in Phoenix.

This search led me to Dr. Suzanne Evans Morris, a personal friend and colleague to this day. Initially, I began to investigate potential treatment to target the improvement of lingual function in the special needs population. This seemed to be a consistent patient treatment issue. Realizing that the jaw is an important key to mature lingual movement, I began to focus on mandibular function. Since that time, we have come to understand that mandibular-lingual dissociation is critical to mature movement of both the tongue and jaw in chewing, and that function of the tongue and jaw are incredibly interrelated in the maturation of oral motor development.

I began to work on designing potential tools to target specific oral motor outcomes. My work eventually led me to the design of a series of tubular tools. I consulted with Dr. Suzanne Morris on the prototype. She began to include the initial tools in treatment with her patients. The tubular design offered a unique resiliency factor to encourage additional biting on the tube. The feedback from patient performance was very positive and families began to ask for these tools for home practice. The prototype was refined. A corrugated handle was added in order that visually impaired patients would have tactile boundaries for grasping the tool. Stem diameters were defined to address jaw excursion ranges in the pediatric population. Parameters of color and content were researched to comply with FDA approved materials. Chewy Tubes were born!

“A Little Something to Chew On”

2. Would you explain the development of Chewing Skills?

The development of biting and chewing skills is a marvelous process of oral motor maturation. There is a gradual refinement of mandibular and lingual motor coordination. Let’s stay with the mandible for the moment. In the initial stage, vertical jaw movement predominates. This is evident in the initial reflexive suckling and sucking behavior of the infant. This vertical pattern of jaw excursion and closure persists through the first three monthsof life and then progresses into the rhythmical phasic bite and release pattern of the infant’s jaw seen at five months of age.

In the 6^th-8^th month period, changes in jaw and tongue function become more evident. In the sixth month, a munching pattern is demonstrated. This stage develops from earlier mandibular and lingual behaviors. The child demonstrates flattening and spreading of the tongue in combination with vertical jaw movement. The munching pattern has been referred to as the earliest form of chewing.

During this oral motor period, tongue movement is still associated with jaw movement, and the pattern of lingual anterior-posterior, extension-retraction movement is predominant in the early feeding patterns of the infant. Instances of diagonal jaw shift are emerging in the fifth and sixth months. Initially this diagonal movement is very slight, but definitely observable to the critical eye of the clinician. When I see this shift occur in the jaw function of my patients it is a moment of joy as I know we are advancing favorably toward our treatment goals.

In the seventhmonth,jaw movement progresses toward a second phase.Diagonal jaw shift now occurs more frequently in combination with vertical jaw movement in manipulation of the bolus during chewing. This emerging diagonal-rotary pattern is supported by the development of lingual lateralization skill which typically develops during the 7th month. This emerging lingual ability allows the tongue to move a bolus from the center to the side of the mouth, positioning the bolus laterally for mastication/chewing. This progression of both jaw and tongue movement adds a new dimension of oral motor function to chewing.

In the 9-12th month period the use of diagonal-rotary jaw movement strengthens, and vertical jaw movement becomes less stereotypic. Interior head, neck and jaw stability are “under construction”. Lingual-mandibular dissociation is now developing as tongue movement gradually separates from jaw movement. This separation allows more lingual skill development, especially anteriorly. This is a fun and exciting period… So much is happening in oral motor development and there are many skills to address in treatment.

In the 12 to 18 month period the diagonal-rotary pattern becomes more consistent and coordinated with lingual lateralization behavior. The child has many opportunities to practice varying amounts of jaw gradation in accommodating new sizes and shapes of food. Strength, tone and repetitive action of the masseter in jaw closure skill targets mastication of more advanced textures that are positioned laterally within the oral cavity by maturing tongue skill. Upper body, head, neck and jaw stability continue to develop.

Between 24 and 36 months, a third pattern of jaw movement emerges in the child’s level of oral motor skill. A circular movement component is added to the rotary chewing component wherein the bolus is positioned laterally for mastication and then transferred by the tongue to the opposite side of the jaw for continued chewing without interruption at the midline. At this third level of jaw skill development, successful mastication prior to the swallow may require that the bolus be transferred repeatedly across the child’s mid- line into each side of the mouth until the chewing process is completed. This third level of skill maturation is referred to as the circular-rotary pattern of jaw movement.

The child’s many and varied oral sensorimotor experiences throughout these early months offer continuous opportunities for maturation of jaw and lingual function. We see increased precision in the amount of jaw gradation and pressure used in biting on various textures. Based on these early sensorimotor learning experiences and the neurological readiness of the child, internal postural stability of the jaw emerges. In feeding treatment, manipulation of the cup on the mandible during drinking experiences assists this development.

During this entire process of oral motor maturation, the jaw along with the tongue is responding to the sensory aspects of the bolus, learning to position, move and masticate food within the oral cavity. Critical aspects of this learning process involve integrating function with characteristics about the bolus such as size, shape, position within the oral cavity, texture, viscosity, firmness, taste and temperature. In addition, the smell of the food itself may impact the child’s acceptance or rejection of the bolus.

MS